Introduction
Patients with asthma typically increase short-acting β2-agonists (SABA) use with worsening symptoms. Excessive SABA use may lead to a higher risk of adverse outcomes. We evaluated, in a large population cohort, an association between SABA inhaler use and asthma exacerbations and healthcare utilization.

Methods
As part of the SABINA (SABA use IN Asthma) global program, we conducted a retrospective longitudinal observational study (SABINA I) using UK primary care electronic healthcare records (Clinical Practice Research Datalink; 2007–2017) from asthma patients aged ≥ 12 years. SABA inhaler use was classified as ‘high use ’ 3 canisters/year versus ‘low use’, 0–2 canisters/year. Taking into consideration all their asthma prescriptions, patients were categorized into a treatment step according to 2016 British Thoracic Society (BTS) asthma management guidelines. Multivariable regression assessed the association of SABA inhaler use by BTS treatment steps (grouped as BTS steps 1/2 and 3–5), separately, and with outcomes of exacerbations or asthma-related healthcare utilization (primary care and hospital outpatient consultations); only patients with linked hospital data were included in this analysis.

Results
Of the 574,913 patients included, 218,365 (38%) had high SABA inhaler use. Overall, 336,412 patients had linked hospital data. High SABA inhaler use was significantly associated with an increased risk of exacerbations [adjusted hazard ratio, 95% confidence interval (CI): BTS steps 1/2 = 1.20, 1.16–1.24; BTS steps 3–5 = 1.24, 1.20–1.28], asthma-related primary care consultations [adjusted incidence rate ratio (IRR), 95% CI: BTS steps 1/2 = 1.24, 1.23–1.26; BTS steps 3–5 = 1.13, 1.11–1.15), and asthma-related hospital outpatient consultations (adjusted IRR, 95% CI: BTS steps 1/2 = 1.19, 1.12–1.27; BTS steps 3–5 = 1.19, 1.13–1.26).

Conclusion
High SABA inhaler use was frequent across BTS steps and was associated with a significant increase in exacerbations and asthma-related healthcare utilization.